Fix: Trim improperly parsed characters from memos.

app/src/main/java/cash/z/ecc/android/ui/util/MemoUtil.kt

@@ -23,21 +23,9 @@ val INCLUDE_MEMO_PREFIXES_RECOGNIZED = arrayOf(
 inline fun ByteArray?.toUtf8Memo(): String {
 // TODO: make this more official but for now, this will do
     return if (this == null || this[0] >= 0xF5) "" else try {
-        String(this, StandardCharsets.UTF_8).trim('\u0000')
+        // trim empty and "replacement characters" for codes that can't be represented in unicode
+        String(this, StandardCharsets.UTF_8).trim('\u0000', '\uFFFD')
     } catch (t: Throwable) {
-        "unable to parse memo"
+        "Unable to parse memo."
     }
-}
-
-
-/*
-        if self.0[0] < 0xF5 {
-            // Check if it is valid UTF8
-            Some(str::from_utf8(&self.0).map(|memo| {
-                // Drop trailing zeroes
-                memo.trim_end_matches(char::from(0)).to_owned()
-            }))
-        } else {
-            None
-        }
- */
+}